Established in 1975, the park represents "one of the largest tracts of pristine marine and coastal environments in the Caribbean," according to Francisco Geraldes, with the Marine Biology Research Center at the Autonomous University in Santo Domingo.

During the 1990s, the 162-square-mile park off the eastern tip of the republic became a poster child for Parks in Peril. The program is a joint effort by the US Agency for International Development and the nonprofit Nature Conservancy to provide critical support to cash-strapped countries in the Caribbean and Latin America that are trying to set aside new land for parks and reserves - or preserve the ones they have.

Now, however, the park has become a symbol of the challenges confronting Caribbean countries as they try to preserve steps taken in the '90s to safeguard important ecosystems against the pressures of population growth and development. Parque Nacional del Este is facing increasing pressures from tourism, while supporters have had to fend off government attempts to open portions of the park to development.

Yet with government support, local resorts, townspeople, and local and international environmental groups are attempting to map a fresh strategy for preserving the park. The conservation plan, which they hope to complete this month, is designed to focus the country's meager resources on preserving and rebuilding the habitats and species that face the greatest threats.

The park's value lies as much in its role as a nursery for marine and landlubber wildlife as in its abundant biodiversity, notes Francisco Núñez, with the Nature Conservancy's office in Santo Domingo.

The park's forests are important as breeding and wintering grounds for a range of migratory and endemic birds. Of the country's 303 bird species, slightly more than one-third breed or mature in Parque Nacional del Este. This has made it a popular destination for bird-watchers, who, in January, included First Bird-Watcher Jimmy Carter. Guerrero, who headed the Carter family's expedition into the park, notes the former president logged his 1,000th species on the trip.

Along the coastline, extensive beaches, reefs, and mangrove swamps provide a similar nursing ground for marine life. "There are not many places like this in the Caribbean," he says.

Trimming the list of endangered species

Yet from a conservation standpoint, "the most critical areas are the marine areas," says Guerrero during a break in a hike up the coral-limestone bluffs that form the eastern edge of the park.

Many of the park's archeological sites attest to how far the area's ecosystem has fallen, Dr. Sealey adds. Based on excavations uncovering Taino Indian waste pits dating back 600 years, "there were lots of turtles, manatees, monk seals, and large sharks," she says. Today, many of these species are endangered. Others have vanished, some as recently as 1996. That year, the World Conservation Union declared the Caribbean monk seal extinct.

"Historically, we've had 200 conch per hectare" offshore, Sealey says, referring to a shellfish prized for its meat as well as its shell. "Now, we have 0.04 conch per hectare. We're talking about order-of-magnitude losses."

How much conservation is enough?

As they weigh options for preserving the park, participants face one of the toughest issues in any attempt to restore critical habitats: How much conservation - which can bring with it restrictions on fishing, boating, and other park uses - is enough?

Trying to answer that question is difficult, even in a developed country. In the United States, restrictions on commercial fishing off the New England coast or felling trees in the Pacific Northwest to preserve endangered species and fragile habitats have cost jobs. However, many of the workers affected by those restrictions have at least some hope of finding other work.

But in the Dominican Republic, which relies heavily on tourism for income and appears to lurch from one economic crisis to the next, "people are really scrambling," says Kathleen Sealey, a marine biologist at the University of Miami, who has done extensive work in the country. "The situation is much more acute."

She is concerned, she adds, that "we're heading in the Caribbean toward the same state that conservation got to in Africa - this clash between environmental groups and development groups. Ultimately, the issue boils down to development."

The point is not lost on Guerrero, who heads Ecoparque, a nongovernmental organization headquartered in his modest Bayahibe apartment. Ecoparque raises money to help pay for park expenses, trains volunteer rangers, and brings the story of the park's ecological role to classrooms throughout the local region.

He notes that efforts to draft a conservation plan for the park have included input from fisherman, representatives from the local hotels and resorts, as well as tour operators and leaders from the three local communities that rely on park visitors for much of their income.

Tourism's boost and liability

In developing a state-of-the-park assessment, which will serve as the basis for the new management plan, tourism has proved to be its biggest benefactor and perhaps its biggest threat, Guerrero and others say.

Tour and resort operators recognize that the park is an enormous asset to them, he explains, noting that these groups were key allies in blocking a government proposal two years ago to open a portion of the park to development.

Moreover, fees charged to the park's 300,000 visitors a year provide the government with badly needed income, which is used to support the country's entire national-park system.

Yet, he adds, tour boats with powerful engines stir up sediment, destroying portions of the mangrove forests, while cruise ships drop anchor over fragile reefs. Even overfishing appears to be a tourism-driven phenomenon, according to Mr. Núñez. When it comes to meals, he says, locals buy chicken; the demand for seafood comes largely from tourists.

Sealey adds that the landed portion of the park faces its own threats - from invasive species and feral livestock, which threaten the habitats of the few small mammals that are native to the island, to local residents who still foray into the woods to gather wood for cooking.

And while the government has established regulations to help protect the park, enforcement efforts are woefully underfunded. Guerrero says part of that problem could be remedied if the government returned to the park a larger share of the money the park earns.

Slow as a turtle, but moving in the right direction

The Nature Conservancy's Núñez sees hope for the process in similar efforts that it has undertaken with the Environment Ministry in other national parks within the Dominican Republic.

He gives the government high marks for its receptivity and "good will." But, he adds, "the nature of the system is that things move slowly."

Sealey agrees that time is of the essence. Preservation efforts may be moving too slowly "for the rate of environmental impacts" that threaten the park.